<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>京东直角三角形</title>
  <style>
    .price {
      margin: 50px auto;
      width: 160px;
      height: 24px;

      line-height: 24px;
      text-align: center;
      font-size: 14px;

      border: 1px solid red;
    }

    .miaosha {
      position: relative;
      float: left;
      width: 90px;
      height: 100%;

      background-color: #f00;
      color: #fff;
      font-weight: 700;
    }

    .miaosha i {
      position: absolute;
      right: 0;
      top: 0;

      width: 0;
      height: 0;
      line-height: 0;
      font-size: 0;
      border-top: 24px solid transparent;
      border-right: 12px solid #fff;
    }

    .origin {
      color: #666;
      font-size: 12px;
      text-decoration: line-through;
    }
  </style>
</head>

<body>
  <div class="price">
    <span class="miaosha">￥1650.00
      <i></i>
    </span>
    <span class="origin">￥5088.00</span>
  </div>
</body>

</html>